1. Field of the Invention
The following description relates to methods of manufacturing an active matrix substrate and an organic light emitting display device.
2. Description of the Related Art
Recent flat panel display devices are driven using an active matrix method, where a light emitting device is formed on an active matrix substrate that includes a plurality of thin film transistors.
With regard to recent flat panel display devices, a light emitting device is formed with an active matrix substrate that includes a thin film transistor and is driven using an active matrix method. In particular, an organic light emitting display device includes a thin film transistor formed with a poly silicon material. When a low temperature crystallization method is used for forming the poly silicon material, the process of manufacturing the flat panel display devices is very complicated, and thus productivity is reduced.
That is, in order to form the active matrix substrate, a large number of patterning processes are required. Also, a photolithography process is employed, wherein photo masks corresponding to desired patterns are used in each of the patterning processes.
Furthermore, in order to realize a complementary metal-oxide semiconductor (CMOS), at least two more photo processes are required before performing the process for doping a semiconductor active layer, and thus, at least two more photo masks must be provided for the photo processes.
Accordingly, manufacturing costs are increased due to the many pieces of equipment used for performing the photo processes, and an overall process time is increased due to the photo processes, thereby reducing productivity.
Also, low productivity is caused by particles generated during various processes.